1. Field of the Invention
The present invention relates to a hair clipper having a comb-shaped stationary blade and a comb-shaped moving blade to cut hairs by clipping between the stationary blade and the moving blade with pressing the moving blade toward the stationary blade by a spring.
2. Description of the Related Art
A conventional hair clipper generally comprises a blade block with a comb-shaped stationary blade and a comb-shaped moving blade to cut hairs, a main body including a motor and a driving mechanism to transfer the driving force to reciprocation of the moving blade, and a pressing spring to press the moving blade toward the stationary blade so as to cut the hairs well.
Conventionally, a pressing spring to press the moving blade to the stationary blade is installed in the blade block. Therefore, a number of elements that constitute the replaceable blade block becomes larger, and it causes the reduction of assemble workability and the increase of the cost of the blade block. In particular, in the use of barber shop with high frequency of usage or in the medical use where the razor must be disposed essentially, it is required to reduce the running cost of the replaceable blade block of the hair clipper.
Japanese Laid-Open Patent Publication No. 56-1188 discloses a structure to install a pressing spring on a main body of a hair clipper. In such a conventional structure, the pressure of the pressing spring, however, is always applied to a blade holder through the moving blade, and a reaction force from the blade holder always acts on the pressing spring in reverse. When the blade block is stocked in a long term under the condition that the reaction force acts on the blade spring, fatigue or compression buckling may occur in the pressing spring in the term of stock due to the reaction force, and thus, the sharpness of the blade may be decreased. Furthermore, when the moving blade is reciprocated frequently, a large friction force occurs between the moving blade and the pressing spring, so that the pressing spring may be galled or deformed due to the friction force, and thereby the life of the blade block may be shortened. Still furthermore, pressing point of the moving blade by the pressing spring may be varied due to the galling or deformation of the pressing spring, so that the pressing force of the pressing spring may be varied. Consequently, the sharpness of cutting by the moving blade and the stationary blade becomes unstable, and desired sharpness of the cutting blade cannot be obtained.
Alternatively, it is assumed that a contact portion of the pressing spring is stationary engaged with the moving blade so as to remove the friction between the contact portion of the pressing spring and the moving blade. When the moving blade is stopped at an end of the reciprocal motion not the center, the contact portion of the pressing spring is held in a state that the contact portion is pulled in an oblique direction. That is, a tension in the oblique direction acts on the contact portion of the pressing spring further to the pressure to press the moving blade toward the stationary blade and the reaction force thereof, simultaneously. Under such a condition, when the blade block is stocked in a ling term, fatigue and/or deformation of the pressing spring may occur in the term of stock so that it causes the deterioration of the sharpness of cutting.